A sliding component using a ceramic sintered body has been applied by taking advantage of the wear resistance thereof, for example, to a mechanical seal that is one of shaft sealing devices for the purpose of completely sealing fluid in rotating parts of various kinds of machines. The mechanical seal includes a mechanical seal ring.
The mechanical seal ring is made up of a rotary ring that slidingly contacts the rotating parts of the various types of machines, and is movable in the axial direction in accordance with the wear of a sliding surface, and a stationary ring being immovable. The mechanical seal ring functions to restrict the fluid leakage at an end face substantially vertical to a relatively rotating shaft.
As the mechanical seal with the mechanical seal ring, patent document 1 proposed the mechanical seal device to abuttingly seal a first sliding member for sealing and a second sliding member for sealing. The first sliding member for sealing uses silicon carbide as the base material, and contains carbon. The second sliding member for sealing contains silicon carbide as the main ingredient, and has independently dispersed pores having a pore diameter of 5 to 200 μm.
FIG. 6 is a sectional view of the mechanical seal device according to an embodiment proposed in the patent document 1. The mechanical seal device 50 shown in FIG. 6 is disposed between a seal housing 51 and a rotary shaft 52. The mechanical seal device 50 is constructed as follows. That is, a seal ring 53 as a fixed-side ring, and a mating ring 54 as a rotation-side ring are assembled through their respective sliding surfaces 53a and 54a, and these two sliding surfaces function as a sealing surface and a rotating contact surface.
The seal ring 53 is attached to a seal housing 51 through a cartridge 55, and the mating ring 54 is attached to the rotary shaft 52 through a support part 56.
The seal ring 53 as the fixed-side ring is pressed by the elastic force of a spring 58 through a bellows 57 so as to be press-contacted against the sliding surface 54a of the mating ring 54 through a sliding surface 53a. The bellows 57 is fixed by a first attachment portion 60 and a second attachment portion 61. The spring 58 is held between the first attachment portion 60 and the cartridge 55.
On the other hand, the mating ring 54 as the rotation-side ring is press-contacted against the sliding surface 53a of the seal ring 53 through the sliding surface 54a, and is attached to the support part 56 through a gasket 62, thereby being rotatable together with the rotary shaft 52.
Thus, the mechanical seal device is proposed in which the seal ring 53 is the sliding member for sealing using silicon carbide as the base material, and containing carbon; and the mating ring 54 is the sliding member for sealing containing silicon carbide as the main ingredient, and having the independently dispersed pores having the pore diameter of 5 to 200 μm.